Used this company to repair my old Birkenstocks and they did a fabulous job and really speedy turnaround.

http://www.footwise.com/Repairs/repair.cfm

I have a few pairs of Birkenstocks but my oldest ones are super comfy so Im really pleased they will see a few more years of wear.

If you have old Birkenstocks that need a little TLC check this site out for great service and repairs.